I was on opt for until November 2011 and on h1b starting October 2011 for the same employer. I got only one W-2 form from my employer. How should I file my taxes? Do I need to file both, 1040NR and 1040? How do I split the income between these forms

If you did not complete 5 years on F1 and OPT, you will file nonresident tax return and form 8843. You will claim treaty deduction as you have OPT income.

I am pretty sure that I need for fill 1040 and 1040NR according to this : http://www.irs.gov/publications/p519/ch06.html
My problem is that I received only 1 W-2